Blood and cardiovascular diseases are both common and deadly. These diseases are chronic, debilitating and they warrant novel therapies. The blood and cardiovascular programs have a number of overlapping features as both are lateral plate mesodermal derivatives and both are coregulated by highly intersecting networks of transcription factors, signaling cascades and extracellular cues. The projects undertaken at our institution will define the key regulatory nodes in the networks that promote stem cells and progenitor cells to adopt a hematopoietic and cardiovascular cell fate - with an aim toward improving clinical options. We will decipher the intracellular, extracellular and paracrine factors that promote stem/progenitor cell specification and differentiation to cardiac, vascular and hematopoietic restricted lineages. In these projects, we will utilize an array of tools and emerging technologies including transgenic mouse models, genetically engineered embryonic and induced pluripotent stem cells, clonal cardiac progenitor cell populations, the decellularized heart, and state-of-the-art high resolution imaging/spectroscopy technologies, which will facilitate our studies and those of our collaborators at the University of Wisconsin and those associated with the NHLBI Progenitor Cell Biology Research Consortium. The overall goal of this proposal is to mechanistically decipher the intracellular and extracellular networks that govern specification and differentiation of stem cells to the cardiovascular and hematopoietic lineages. To address this overall goal, we will pursue the following projects: Project #1: To define the transcriptional mechanisms that specify the hematopoietic program in hESC- and hiPSC-derived mesoderm. Project #2: To define the transcriptional and signaling networks that specify the cardiovascular program In mES/EBs, hESC, hIPSC, and cardiac progenitors. Project #3: To define the extracellular cues including cell matrix interactions that direct cardiovascular differentiation and function. Project #4: To define the optimal cell populations derived from hESCs and hiPSCs for myocardial regeneration. The results of these collaborative studies will serve as a platform for emerging therapies for blood disorders and cardiovascular disease.